Self-baking electrode



Jan. 4, 1927, l,613,2l2

EEEEEEEEEEEEEEEEE DE JI I Paimta J.. -4,- 1927. i

vUNrrEn sTATEs PATENT OFFICE.

JENS WESTLY, OF CHBISTIANSAND. NORWAY. ASSIGNOR TO NOBSKE AKTIESEL- SKAB FOR ELEKTROKEMISK INDUST'RI OF NORIVAY, vOF OSLO, NORWAY.

SELF-BAKINGl ELECTRODE.

Application flled January 5, 1925, Serial No. 711, and in Norway January 17, 1924.

This invention relates to selfbaking electrodes,' that is, electrodes which are baked in the furnace in which they are used, and lthe object of the invention is the provision of a contact supplying electric current to the electrode without substantial loss of voltage.

In U. S. Patent No. 1,440,724 there is described self-baking eleetrodes provided w'th metallic mantles. In said.patent.it is s ated that one of the functions of the more or less of this dust may be c'arriedl in between the contact surfaces, causing a certain resistance and consequent voltage loss. This loss of voltage is generally quite negl'gible compared with the' total voltage .50 of the furnace. In certain special cases it may,'however, be .of importance to a'voidV :this loss ofvoltage. An excellent .example is the application of the electrode in furnaces for the production of aluminium, as the total voltage of the furnace in this case is only 6,5-7 volts. If for instance the drop in voltage from holder to electrode is 0,35

volts this amounts .to 5% of the total voltage. In furnaces' for the production of 40 aluminium it has been propos'ed to su ly electrodes with "aluminium mantles; Ji'xis metal readilbecomes coated with a thin oxide film o ering considerable resistance to' the passage of the current. The lossiof voltage may therefore easily become relauively large and precautions should'be taken to reduce the resistance. For this purpose I have found it desirable to employ a dontact arranement which in its principle isshown .in drawing formin'g part of this application.

4 n modification in which the., mantle is provided with -a number of. straps which 5 are bent so as to extend outwardly the drawing Fig; 1 illustrates a from the elcctrode and to which the contact arrangements are firmly attached. Fig. 2 shows -a (ontact arrangement clamped on to two straps. Figs. 3 and 4 are sectionsthrough Fig; 1. 1 is .the electrode, 2 the mantle and 3 one of the two straps which are held tightly between the two metal blocks/' and 5 by means of the boltand nnt 6. ,Thus' the contact becomes practically perfect and little or no loss of voltage can be found in the contact. At the same time the arrangement possesses the advantage that the contacts may be raised one at a time while the other contacts maintain the l supply .of current, no disturbance in the working being caused during the raising.

The independent electrical contacts may be made in different ways, for example by clamping bto straps a's above described, or by direct pressure against the surface of the sheet metal, or' by clampin conductors firmly against the surfaces of t e externally projecting portions of the ribs, as heroin-b after descri ed. If .the current is supplied directly to the ribs -the metallic mantle may Ibe left out and for instance be re laced by a mantle consisting of netting., f the nettin is of sufliciently fine meshes it will keep t e mass inside during the baking.

The suspension of the'electrode may be efiected by means of the contact arrangements, butit is preferable to employ a spelcial supporting. electrode-holder. such as illustrated at 2' Figure 1, which for instance clamps around the electrode. In many cases it is advantageous to .lae the contactarrangement at a consi erable height above the bath. Tovreduce the drop in voltage it is often advantageous to'reinforce the ribs or prolongations to which the contact arrangement is attached. This may for instance be done by castinsaluminium around.

the external parts of ri as shown in Fi' 3,. in which 1 is the electrode, 2 the' mant e and v3' theq metal cast around the external parts of the ribs. v

My contact arrangement may also be employed in connection with hollow selfbaking electrodes where the electric current is supplied throu h a, contact arrangement placed in the annel. Such an arrangement is shown in U; S. Patent No.'1,442,031. The channel is provided with a suitable metal linin'g, for instance in the form of a' tubehavingthin .The tube may if v`desired be provided -with holes .to let out the gases formed during the baking of the electrode. The contact arrangement may for example be so made that it projects into the channel and grips around projections of the armature and (or) the extensions of the ribs.I Fig 4 shows an electrode provided with such extensions, in which figure, leis the electrode;`2b the ribs having projections 31 extending into the channel, and 41? is the metal tube or lining. 1

It is of course to be understood that my invention is not limited to the above illustrations as its mode of application may ,Vary according to the type of electrode used in ea'ch special` case. i

What I claim as new and desire to secure Letters Patent of the United States i'sz';

1. In self-baking electrodes rovid`ed with metallic mantles, and electrodle supporting means Ifor controlling the Position and feeding of the electrode, separate electrical contacting means independent of said electrode supporting means and' adapted to` introduce current into the electrode with a minimum loss in voltage at their contact therewith.

2. In self-bakin' electrodes provided 4.with metallic man es, electrical .contacting means, attached to portions of said mantles and distinct from the eletrode supporting means, adapted to minimize the voltage less, where current isintrod'uced intoithe electrode.

the electrode, for the 3. Inielectrodes of the kind described, a 3 plurality of'electrical contacting means, independent? of the electrode supporting means and independently adjustable, adapted to introduce current into the electrode with a minimum drop in voltage at the contacts. 4

4. In electrodes of the kind described, independent electrical contacting'means comprising conductors firmly attached to projecting portions of themetal mantle around purpose of leading the 4 current into it.

5. Contact arrangement for self-baking electrodes/ provided with metallic mantles com rising a plurality of projections and condhcting members attached thereto ofwhich a number smaller than the total number is capable of transmitting the current to the electrode. 1

6. In electrodes of the kind described, metallic ribs projectin metallic `mantle and a apted to make contact vWith electrical' contact means inV the external circuit and conduct the current into the electrode.

radially from, the 55 7.' In electrodes of the kind described out- 00 wardly extending metallic contact ribs forming integral continuations of the' internal reinforcing ribs, and firmly attached to the mantle` and adapted to receive the electric current from the external circuit and trans- 65 fer to the electrode.

JENs wEs'rLY. 

